Musicality. The treated paper cone was very quick and nimble, but not thin. My priorities are Music first and HT a distant second. Frequency response. 40 hz F3 worked perfectly in a sealed cabinet. A stereo pair in the corners gave complimentary boundary gain/roll off for flat response to 25 hz in my room. The subs performed flawlessly up to 120 hz and were easy to integrate with my main speakers. Build quality. Cast aluminum frame and large voice coil. At $99 each they were a steal.

I do not know how I missed this thread I do not seem to receive post notifications on occasion.

15 years ago, it was a more difficult to find a driver that suited my purpose, thus a custom built driver was necessary. A few years later, something similar would have been on the shelf available from TC Sounds, etc... Today, I'm too far departed from that realm to advise you. After almost an hour of searching, I still could not find the specs. If I come across them in the near future, I'll post them here.